It's a familiar sound on streets up and down the land wherever construction work is taking place – a builder spots an attractive woman walking along and belts out a charming wolf-whistle.

But those working on security fencing jobs could soon be weaned off the wolf-whistle – and it comes in the unlikely shape of a hard hat.

Yes – a new hard hat has been launched which is designed to stop construction workers wolf-whistling at passing women.

Called the "Stop That Hard Hat", the device is equipped with small speakers which play pre-recorded messages to the offending builder whenever they detect a wolf-whistle.

It uses a two-stage warning system to alert builders that their behaviour is not welcomed.

The first whistling prompts a warning about site behaviour.

And if they dare to do it again, they'll be treated to piped versions of classic feminist texts by Germaine Greer and Andrea Dworkin.

Manufacturers of the hat believe it will end sexist behaviour on sites. Curiously-titled spokesperson Avril Una said: "The construction industry has made great strides in this field but many women are still intimidated walking past building sites.

"We believe this product will provide a constant reminder to builders of the consequences of their behaviour."

The manufacturer is believed to be working on a number of other products – due this time next year – including trousers that eradicate the unsightly builder's bum and a pill which suppresses the desire for tea drinking.

(Oh, and yes, we know this is an April Fools.)ADNFCR-3337-ID-800483851-ADNFCR